The present application has been filed concurrently with U.S. patent application, Ser. No. 855,587, filed Apr. 23, 1986, and assigned to the Assignee of the present application.
1. Field of the Invention:
The present invention relates to the field of electronic power amplifiers, and more, specifically to power amplifiers for driving a shaker.
2. Prior Art:
There are a considerable number of "shakers" that are well-known in the prior art. These shakers are used to mechanically shake an item for the purpose of diagnostically testing responses to certain driving forces. The item is physically attached to a moving portion of the shaker and when the shaker is activated, the item is subjected to a variety of test conditions. The moving portion of the shaker is typically driven by a force which may be continuous, cyclical or impulsed.
One class of these shakers employ the use of an electromagnetic field between field and armature windings. Various driving signals are impressed across the armature winding to control the movement of the shaker. A variety of sensing devices are also employed to provide feedback to the main control unit. To drive this type of a shaker, a power supply is needed to provide electrical power to the field and armature windings. Typically, the voltage on one winding (the field winding) is kept constant while the other winding (the armature winding) is driven by a varying signal which then varies the electro-magnetic field for moving the shaker.
In the prior art, shaker power supplies were custom designed for a particular shaker, or in many instances, the nearest acceptable unit meeting the shaker requirement was configured for use. Further, many prior art shaker power supplies did not provide the precise electronic controls for closely monitoring and controlling the electrical drive of the shaker.
As will be disclosed, the present invention provides a shaker power source which is readily adaptable to meet most armature type shaker power requirements, and also provide precise control over the electrical drive of the shaker.